Orthopedic head and neck support devices are designed to provide users with support and alignment of their head and neck region. A multitude of different orthopedic head and neck support device designs exist, and many of these devices use resilient foam materials to provide the necessary support. Flexible polyurethane foams are commonly used in the manufacture of these support devices, as are viscoelastic memory foams.
Unlike polyurethane foams, viscoelastic memory foams are designed to adapt more to the shape or form of a user's head as the user utilizes the device. When a user places their head on viscoelastic memory foam, the foam compresses and conforms to the shape of the user's head. This function of adapting to the shape of the user's head aids in providing a more comfortable support experience for the user. In addition, when the user then removes their head off of the viscoelastic memory foam, the foam returns to the shape it had prior to the compression, thus it is termed memory foam.
One drawback to the use of viscoelastic memory foams in orthopedic head and neck support devices is that when used alone, these foams tend to not offer enough support for the user. Some users consider them too soft for adequate support of the head and neck. So viscoelastic memory foams provide almost instant comfort, but they may be too soft for users and tend to lose their viscoelastic memory properties over time. When this happens, they compress and flatten and remain that way.
Unlike viscoelastic memory foams, polyurethane foams have different compression characteristics that require them to be broken in before the devices can achieve their greatest level of comfort. "Breaking in" a polyurethane foam simply refers to the process of repeatedly compressing the foam of a support device during its initial usage. The compression is caused by the weight of a user's head on the foam when in use. This repeated compression of the foam every time the user is using the device compresses the internal structure of the foam and pushes air out from within the structure. The polymers of the foam tend to "remember" this compressed structure, which makes the polymers tend to bias towards the compressed structure. Through this breaking-in process, the foam becomes softer and more pliable in the area of the compressed structure. And because the area of the compressed structure corresponds to the area where the user's head is pushing down on the foam, the foam is thus "conforming" to the shape of the user's head.
The break-in period for polyurethane foam can last from as little as a few hours to more often as long as several days to a week or more before the foam adequately softens and comfortably retains the shape of a user's head. This long of a break-in period may be unacceptable to potential users who require the head and neck support these devices offer, but are unable to endure the stiffness of a non-broken-in foam due to their medical conditions. For instance, users that have chronic (rheumatoid arthritis) or acute neck disorders (acute inflammation), or that have suffered a recent head trauma or neck injury with muscle spasm, typically cannot withstand any length of a break-in period.
Another drawback of polyurethane foam head and neck support devices is that they provide a single, fixed amount of firmness at any given point in time. This is disadvantageous to potential users because people tend to have any of a wide variety of medical conditions that generally require different amounts of support and firmness. Unfortunately, the foam used in known support devices cannot be adjusted to provide varying degrees of support based on the user's needs.
Accordingly, there is a need for an orthopedic support device that provides comfortable head and neck support, correctly aligns the spine, head, and neck, requires no break-in period, and yet allows a user to adjust the firmness of the support.